Fix maxim max77686 driver

With driver-y going away, the current driver code didn't get
compiled in with upstream.

Change-Id: I9bff45a35c995888a482bdc22a1573f6bfb88211
Signed-off-by: Stefan Reinauer <reinauer@google.com>
Reviewed-on: http://review.coreboot.org/2027
Tested-by: build bot (Jenkins)
Reviewed-by: Ronald G. Minnich <rminnich@gmail.com>
diff --git a/src/drivers/maxim/max77686/Makefile.inc b/src/drivers/maxim/max77686/Makefile.inc
index 3fc7104..b67595f 100644
--- a/src/drivers/maxim/max77686/Makefile.inc
+++ b/src/drivers/maxim/max77686/Makefile.inc
@@ -17,4 +17,4 @@
 ## Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301 USA
 ##
 
-driver-$(CONFIG_DRIVER_MAXIM_77686) += max77686.c
+ramstage-$(CONFIG_DRIVER_MAXIM_77686) += max77686.c